Commutator



' 1,635,886 y 1927' E. GRATTON COMMUTA OR Filed June 2, 1925 upon which is Patented July 12, 1,927.

PATENT OFFICE.

EDWARD ena'r'ron, or DETROIT, MICHIGAN.

- commum'ron.

App'lication filed June 2, 1925. Serial No. 34,498.

This invention relatesto improx ements in commutators and the otnects of the inventlon are to provide an improved tuning device for controlling the electric spark in the igni tion of internal-combustion engines, whereby current flows at predetermined intervals to suitable sparking'elements.

Further objects are to provide a comma tator particularly adapted for use in Ford cars and in which there very little wear and tear. I

With this and other objects in view the invention consists essentially of the/combination and arrangement of parts hereinafter more fully described and referred to in the accompanying specification and drawing. in which:

Figure 1 is an end elevation of my improved commutator, looking at the inside thereof; I

Figure 2 is a vertical section of Figure l;

Figure 3 isa perspective view of the contact arm, I

Figure 4 is a fragmentary sectional detail of the contact arm mount-edv in the casing;

Figure 5 is a perspective detail of the r rotor contact member; i

Figure '6 is a perspective view of the sleeve member; g I

' Figure 7 is an elevation of the insulating washer, and I Figure 8 is a section on the line 8-8 of Figure 7.

Referring now to the/drawings, A indicates the commutator case mounted on the wall D- of the engine. C is a cam shaft mounted the rotary element 1). The casing A is provided with the arm 10 which is used for the purpose of advancing and retarding the spark, the arm 11 being adapted to hold the commutator casing in position on the engine wall. Mounted on the inner periphery of the commutator casing are a plurality 'of ears E. These ears are composed of U-sha ed members 12 with which are integrally ormed threaded pins 13. The threaded pins are adapted to extend through th insulator 14 in the casing A and are secured by the securing nuts 15. The thumb nuts 16 are adapted to engage with the pins 13 and retain in position the current-carrying wires 17. Extending through the U'shaped members 12 are. pins 18 upon which are hingedly mounted the contact arms 19. These contact arms'are connected by cross-members 20 the surface 21 of whlch adapted to contact with the rotor I). Springs 22 substantially U-shaped are also mounted on the pins 18, the arms 23 of which are adapted to contact with the mem bers 20 while the arms 24 are adapted to contact with the inner surface of the casing A, the action of the spring holding the contact members E in contact with the rotor D.

The rotor D comprises a sleeve 25, an insulating washer 26 and a rotor contact member 27. The sleeve is provided with a slot 28 and a shoulder 29. The insulating washer 26 is adapted to fit the shoulder 29 of the sleeve, and is provided with recessed portions 30 and 31 and a slot 32. The member 27 is provided with a contact arm 33 ,which is adapted to fit into the recess 32 of the washer 26, the body of the member 27 fitting the recess 30. When the rotor D is mounted on the cam shaft as illustrated in Figure 2, the pin 34 extends through the slot 28 of the sleeve 25 and into the orifice 35 in the cam shaft C; the washer 36 is then placed in the recess 31 and is retained in position by the cup-shaped cap 37, the member 37 preventing the pin 341 from becoming loose or otherwise disengaged. The securing nut 38 which is secured to the threaded portion of the cam shaft C, prevents the cap 37 from becoming loose'and binds the rotor D in the cam shaft.

When in operation, the rotation of the cam shaft causes the rotor element D to rotate, the spring arms 23 of the spring 22 forcethe contact members 20 to contact with the surface of the rotor D; continued operation of the rotor D' will, as may be observed in Figure 1. cause thearm 33 of the contact member 27 to come in contact intermittently with. the surface 21 of the contact member E, whereby electrical energy through the wires 17 is grounded, the ground circuit beingcompleted through the members 12, 20, 27, 25 to the shaft C.

What I claim as my invention is 1- In a commutator of the character described, the combination with a casing pro vided with an arm for regulating the spark, a cam shaft, a plurality of binding posts in the casing, spring actuated pivotally mounted arms on said binding posts, a sleeve for the cam shaft formed with an annular shoulder and a slot in one end, an insulating washer adapted to contact with said arms and formed with a central annular recess adapted to fit on th sleeve and to engage with the shoulder thereon, a slot in the washer communicating with the annular reeess, a contact member adapted to fit on the shaft and into the annular recess in the Washer, an extension integral with said 1118111- ber provided with an arm having its end adapted to fit flush with the periphery of the Washer, a securing pin adapted to engage with the slot in the sleeve and to extend into the shaft and a cup shaped cap screw 10 threadedto engage with the screwthreaded end of the shaft and designed to retain the securing pin in position.

In Witness whereof I have hereunto set my hand EDNVARD GRATTON. 

